1. Field of the Invention
This invention, relates, in general, to vehicle roof structures and, more specifically, to vehicle roof structures incorporating a sliding roof panel for selectively opening and closing an opening in the vehicle roof.
2. Description of the Prior Art
In todays automobile market, a popular vehicle option is the so-called "sun" or "moon" roof in which a movable panel is retractable between closed and open positions in an opening formed in the vehicle roof. The movable roof panels are typically formed of a transparent material, such as glass or plastic, to allow light to enter the interior of the vehicle when the panel is in the closed position.
Such movable roof panels are conventionally moved along a track assembly extending longitudinally along each side of the roof opening and mounted between the edges of the roof opening. The entire track assembly is usually inclined so that the movable roof panel is stored or nested beneath the rear stationary roof panel when the movable panel is in the open position. The movable panel rises vertically as it is moved forward to the closed position so that, when in the closed position, the movable roof panel is flush with the adjacent roof structure. A compressible seal member is provided on either the roof structure or the closure panel which is compressed between the penels as the movable panel reaches its closed position.
A disadvantage of the prior art movable roof panel structures is that a relatively complex guide track mechanism is necessary to move the panel between the open and closed positions. This not only increases the expense of the movable roof structure and the vehicle weight, but also, complicates installation of the movable roof panel assembly onto the vehicle. Further, the length of conventional movable roof panels in conjunction with the inclined surface of the guide track assembly requires additional space within the interior of the vehicle to store the roof panel in the open position. This reduces the available headroom within the vehicle and makes the movable roof panel structure less desirable. Finally. it is common for operators of vehicles to leave the movable roof panel somewhere inbetween the fully opened and fully closed positions, either to reduce the incoming flow of air or due to external weather conditions. It becomes necessary to securely hold the panel in the desired partially opened position.
Therefore, it is desirable to provide a movable roof panel structure for vehicle roofs which utilize a more simplified guide track mechanism for guiding the movable panel between open and closed positions than previous prior art roof structures. Also, it is desirable to provide a movable roof panel structure which requires less space within the interior of the vehicle for storing the movable panel in the open position. Finally, it is desirable to provide a movable roof panel structure which may be securely disposed in a plurality of partially opened positions.